Thomas welch



@latten tatrs iQue-tent @frn Letters Patent No. 72,844, d ted December 17, 1867.

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TO ALL WHOM IT MAY CONOERN:

Be it known that I, THOMAS WELCH, of Churchville, in the county of Monroe, and State of New York,- have invented certain new and useful Improvements in the Construction of Pitmen for Harvesters; and I do hereby declare that the following is a full, clear, and exact `description thereof, reference being had to the accompanying drawing, making part of this specification, in'ivhch* Figurel isaftcp-view' of my invention, the head Han'd set-screw Svbeing shown inseetion, taken in thev plane'indicated by the red line z'in tig. 2.

Figure 2 is a side view of the head H, and a section of the ptman P.'

The nature of this invention consists'mainly in providing a skeleton cast or malleable-iron pitnran for har' vesters, having a shell-head or ease to receive the box of the crank-pin; and in strengthening the seid pitman with a wooden .stock riveted or otherwise securely attached to it; and, also, in such a construction ofthe pitlnanhead and crank-pin box as to permitany changes in their relative position that may be required by-theaction of the machine.

To enable others to make and use my invention, I will describe its construction and operation.

I make the pitman Pof any desired form or length. A transverse section of that shown in the drawings is Ushapef`l, it being composed of a. flat base or back, A, from each edge of which is a projecting flange, B. If the casting is made very light, I would strengthen it by inserting a wooden stock, O, in the space between the flanges B', as shown, where itwould be scoured by rivets or other suitable means.

The skeleton or shell-head -H is cast with the pitman, and it is cored out where the set-screw S is inserted, The core is also made to form the spherical concave, at a,- 'or the spherical back', b, of that half ot the box B. '[he other half of the box is supported by the endof theset-serew S.

By means of this construction and arrangement of the parts, the pitman and head are permitted to react upon the box, and thc lower end of the pitman is allowed to vibrate longitudinally, as required by the changes in the relative position of the cutterbsr to the front r rear. I

The outer end of the crank-pin D is grooved, us indicatedI by' the dotted line c, and the halves of the box provided with a iiangc or rim to t it. This secures the box and head to the pin. f

The set-screw S is made large enough` to aiford a suilicient cavity in the end for the proper support of that side of the box; and, in order to have it lightiand cheap, I make it of Vcast iron, and hollow, a-s seen in iig. 1. It may be cored out square, and 2t iv'ren'ch having a square shank used for turning it; or there may be n square formed on the outer end, as seen in iig. 2. The pitman is attached to the crank-piu by placing the box upon thc pin, and then slipping the head H ofthe pitman over them properly; and the set-screw S is then turned in until the proper relative adjustment of the-parts is secured, which is thenvtixed by the jam-nut F.

The pitman may be made with flanges, B', projecting both ways Vfrom the connecting 1web or plate; or there may be a single rib on one or both sides; or it may be made diamond-shaped, or triangular, tc.

The pin Gr may be cas-t to the pitman, and made hollow, as indicated by the dotted lines e; or the pitman may be attached to the knife-bar head by a pin or bolt, as may bedesired. It will be seen that this head, H, may be made separately, aud attached to the pitman in any suitable manner.

What I claim as my invention, anddesire to secure by Letters Patent, is

1. A skeleton or shell-pitman for harvesters, made of suitable cast metal, the skeleton or'shell-head to receive the crank-pin box being cast to andwith the Pitman, for the purposes set forth,

2. The crank-pin boxes with spherical bearings, in combination with a. pitman-head having a suitable concavity, as and for the purposes specified. y

3. A set-'screw having a. concaved end, when used with the Pitman-head and crank-pin box in harvesters,

for vthe purposes set forth.

THOMAS WELCH.

Witnesses:

WM. S. Louennonouen, A. H. BrLLINes. 

